1. Technical Field
The present invention relates to an electronic component-embedded printed circuit board and a method of manufacturing the same.
2. Description of the Related Art
Various technologies are required to realize printed circuit boards (PCBs) in a market which requires semiconductor packages to have decreased profiles and a variety of functions.
Recently, the development of chip-embedded printed circuit boards has attracted considerable attention as part of next-generation multifunctional and small-sized packaging technology. Chip-embedded printed circuit boards must be designed to take into consideration high-functionality as well as the advantages of multi-functionality and miniaturization because they can improve the connection reliability problems occurring during the wire bonding for mounting flip chips or a ball grid array (BGA) or during a process of electrically connecting semiconductor chips using solder balls. Particularly, as printed circuit boards have become light, thin, short and small, ultra-precise packaging technologies have attracted considerable attention. In particular, in a soldering process for forming an electrical connection between a substrate and a main board or a molding process for mounting a substrate with a chip, it is increasingly important to improve the warpage of a semiconductor substrate. The warpage of a semiconductor substrate influences processing ability and productivity. Further, the warpage of a semiconductor substrate is a very important factor in causing the problem of solder balls not being formed on the solder ball pads of a semiconductor substrate during a soldering process, the problem in which semiconductor elements are not attached to solder balls formed on a semiconductor substrate at the time of mounting the semiconductor substrate with the semiconductor elements, and thus the problem in which the semiconductor elements do not electrically communicate with the semiconductor substrate. Moreover, the warpage of a semiconductor substrate may result in abnormal operation during transportation, molding or singulation.
FIGS. 1A to 1E are sectional views sequentially showing a conventional method of manufacturing an electronic component-embedded printed circuit board, in which both sides of the printed circuit board are symmetrical to each other in order to prevent the warpage of the printed circuit board. Hereinafter, conventional problems will be described with reference to FIGS. 1A to 1E.
First, as shown in FIG. 1A, there is provided a substrate 100 including: an insulation layer 130 having a cavity 120 in which an electronic component 200 can be disposed and first circuit patterns 110 formed on both sides thereof; and a tape 140 adhered to one side of the insulation layer 130.
Subsequently, as shown in FIG. 1B, the electronic component 200 is disposed in the cavity 120 of the insulation layer 130. In this case, the electronic component 200 is installed in the cavity 120 in a face-up manner using a vacuum adsorption header (not shown), and is supported by the tape 140.
Subsequently, as shown in FIG. 1C, an insulating material layer 150 is formed on the substrate 100 including the cavity 120. The insulating material layer 150 is formed in the cavity 120 provided therein with the electronic component 200, and thus the electronic component 200 is buried in the insulating material layer 150.
Subsequently, as shown in FIG. 1D, the tape 140 is removed from the substrate 100. Since the tape 140 serves to support the electronic component 200 before the electronic component 200 is fixed in the substrate 100 by the insulating material layer 150, it is removed after the insulating material layer 150 is formed. Then, the insulation material layer 150 is secondarily formed on the substrate 100 from which the tape 140 has been removed, thus entirely burying the electronic component 200 in the insulation material layer 150.
Subsequently, as shown in FIG. 1E, an insulating material layer 150 is formed even on the one side of the insulation layer 130 from which the tape 140 was removed, so that the electronic component 200 can be embedded in the substrate 100, and then circuit layers 180 including vias 160 and second circuit patterns 170 are formed on both sides of the insulating material layer 150. In this case, the vias 160 are electrically connected with the connecting terminals 210 of the electronic component 200.
However, the above electronic component-embedded printed circuit board is problematic in that it is difficult to make the printed circuit board to be light, thin, short and small because both sides thereof must be symmetrical to each other, and in that reliability of the connection is decreased because the connection terminals 210 of the electronic component 200 cannot be directly connected to the first circuit pattern 110. In order to solve the above problems, a new printed circuit board that is light, thin, short and small because an insulation material layer is not formed on one side thereof was proposed. However, this printed circuit board is also problematic in that it easily warps because both sides thereof are asymmetrical to each other unlike the conventional printed circuit board. Further, this printed circuit board is problematic in that, when an electronic component is disposed therein in a face down manner, a circuit layer connecting with the connection terminal of the electronic component is not suitably brought into contact with a substrate.